Integrated positron emission tomography and computed tomography in preoperative lymph node staging of non-small cell lung cancer

Background Integrated positron emission tomography and computed tomography （PET/CT） is increasingly used for the preoperative nodal staging of non-smail cell lung cancer （NSCLC）.The aim of this study was to evaluate the accuracy of PET/CT in comparison with CT in detection of nodal metastasis and preoperative nodal staging in patients with NSCLC,and to analyze the causes of the PET/CT false-negative and false-positive results.Methods Consecutive patients with pathologically proven NSCLC who underwent staging using PET/CT from July 2008 to February 2012 were evaluated retrospectively.Nodal staging was pathologically confirmed on tissue specimens obtained at thoracotomy.The accuracy of PET/CT and CT in the assessment of intrathoracic nodal involvement was determined using histological results as the reference standard.Logistic regression was used to define the causes of the false-negative and false-positive results.Results A total of 528 lymph node stations were evaluated in 101 patients.Lymph nodes were positive for malignancy in 43 out of 101 patients （42.6%）,and 101 out of 528 nodal stations （19.2%）.PET/CT was significantly more accurate for nodal staging than CT.The sensitivity,specificity,positive and negative predictive values,and accuracy of PET/CT for detecting nodal metastasis were 51.5%,95.8%,74.3%,89.3%,and 87.3% and the corresponding data by CT were 45.5%,87.1%,45.5%,87.1%,and 79.2%,respectively.PET/CT confers significantly higher specificity,positive predictive value,and accuracy than CT in detecting nodal metastasis.False-negative results by PET/CT are significantly associated with smaller lymph node size,whereas false-positive results are related to a combination of inflammatory disorders and larger lymph node size.Conclusion PET/CT confers significantly higher accuracy than CT in nodal staging,and is more specific and accurate than CT in detecting nodal metastasis but has a low sensitivity and high false-negative rate.

Modelling the probability of erroneous negative lymph node staging in patients with colon cancer

Background:Patients in who with insufficient number of analysed lymph nodes(LNs)are more likely to receive an incorrect LN staging.The ability to calculate the overall probability of undiagnosed LN involvement errors in these patients could be very useful for approximating the real patient prognosis and for giving possible indications for adjuvant treatments.The objective of this work was to establish the predictive capacity and prognostic discriminative ability of the final error probability(FEP)among patients with colon cancer and with a potentially incorrectly-staged LN-negative disease.Methods:This was a retrospective multicentric population study carried out between January 2004 and December 2007.We used a mathematical model based on Bayes’theorem to calculate the probability of LN involvement given a FEP test result.Cumulative sum graphs were used to calculate risk groups and the survival rates were calculated,by month,using the Kaplan-Meier method.Results:A total of 548 patients were analysed and classified into three risk groups according to their FEP score:low-risk(FEP<2%),intermediate-risk(FEP 2%-15%),and high-risk(FEP>15%).Patients with LN involvement had the lowest overall survival rate when compared to the three risk groups.This difference was statistically significant for the low-and intermediate-risk groups(P=0.002 and P=0.004,respectively),but high-risk group presented similar survival curves to pN+group(P=0.505).In terms of disease-free survival,the high-risk group presented similar curves to the intermediate-risk group until approximately 60 months’follow-up(P=0.906).After 80 months’follow-up,the curve of high-risk group coincided with that of the pN+group(P=0.172).Finally,we summarized the FEP according to the number of analysed LNs and accompanied by a contour plot which represents its calculation graphically.Conclusions:The application of Bayes’theorem in the calculation of FEP is useful to delimit risk subgroups from among patients without LN involvement.

Clinical value of regional lymph node sorting in gastric cancer

BACKGROUND Increasing evidence have shown that regional lymph node metastasis is a critical prognostic factor in gastric cancer(GC).In addition,lymph node dissection is a key factor in determining the appropriate treatment for GC.However,the association between the number of positive lymph nodes and area of lymph node metastasis in GC remains unclear.AIM To investigate the clinical value of regional lymph node sorting after radical gastrectomy for GC.METHODS This study included 661 patients with GC who underwent radical gastrectomy at Tianjin Medical University General Hospital between January 2012 and June 2020.The patients were divided into regional sorting and non-sorting groups.Clinicopathological data were collected and retrospectively reviewed to determine the differences in the total number of lymph nodes and number of positive lymph nodes between the groups.Independent sample t-tests were used for intergroup comparisons.Continuous variables that did not conform to a normal distribution were expressed as median(interquartile range),and the Mann-Whitney U test was used for inter-group comparisons.RESULTS There were no significant differences between the groups in terms of the surgical method,tumor site,immersion depth,and degree of differentiation.The total number of lymph nodes was significantly higher in the regional sorting group(n=324)than in the non-sorting group(n=337)(32.5 vs 21.2,P<0.001).There was no significant difference in the number of positive lymph nodes between the two groups.A total of 212 patients with GC had lymph node metastasis in the lymph node regional sorting group,including 89(41.98%)cases in the first dissection station and 123(58.02%)cases in the second dissection station.Binary and multivariate logistic regression results showed that the number of positive lymph nodes(P<0.001)was an independent risk factor for lymph node metastases at the second dissection station.CONCLUSION Regional sorting of lymph nodes after radical gastrectomy may increase the number of detected lymph nodes,thereby improving the reliability and accuracy of lymph node staging in clinical practice.

EVALUATION OF STAGING AGREEMENT BETWEEN CTNM AND PTNM FOR LUNG CANCER

A series of 225 consecutive lung cancer patients were prospectively randomized into a study group (75 patients) and a control group (150 Palients), and the agreement between CTNM (clinical staging) and PTNM (pathological staging) was evaluated. Radical mediastinal lymph node dissection was performed and on an average 11.5 nodes were dissected each case in the study group.Only suspected metastatic lymph nodes, 3.4 on an average,were dissected each cast in the coutrol group. CTNM classification was made according to clinical examination,chest image exainination and bronchoscopy in every patient and PTNM staging was made after thoracotomy.Then the agreement of CTNM and PTNM staging was judged by Kappa value. The results showed that the Kappa value in the two groups was lower than the effective standard value of 0.4, which was poorer in the study groul, (KaPPa=4).097) than that in thecontrol group tKappaed.371). The Principal influencing cause was that N was not well evaluated by CTNM. The priucipal manifestation of the staging iuconsistency was that the stage of PTNM was advanced than that of CTNM. In the study group 43% of patients showeil an increased stage and this occurred in 33% of the control group (P< 0.05).The results of the study show that at present the CTNM staging has not fully satisfied the necds of practice and requires to be further improved. The operative procedure that only suspected involved mediastinal lymph nodes are dissected can not meet the needs of PTNM staging. In order to make PTNM staging accurately and evaluate the results of treatment for lung caucer, radical mediastinal lymph node dissection should be performed in every operable Patient.

Prognostic value of negative lymph node count in patients with jejunoileal neuroendocrine tumors

A negative lymph node(NLN)count has been shown to have a significant impact on the prognosis of many types of cancer.However,its prognostic value for jejunoileal neuroendocrine tumors(NETs)remains unclear.In this study,we investigated the prognostic value of NLN count in patients with resected jejunoileal NETs diagnosed between 1988 and 2014.The data were retrieved from the Surveillance,Epidemiology and End Results database.The X-tile program was used to determine the cutoff value of the NLN count.Univariate and multivariate Cox proportional hazards models were used to assess the prognostic value of NLN count on survival.Harrell concordance index was used to compare the prognostic validity of NLN count with 2 current prognostic systems.The optimal cutoff point of the NLN count was 8.Kaplan-Meier analysis revealed a progressively worse overall survival(OS)with an NLN count≤8 compared with an NLN count>8(P<0.001).Univariate analysis showed that the NLN count,age,tumor site,tumor size and T classification were significant prognostic factors for the OS of jejunoileal NETs,while the number of positive lymph nodes had no significant impact on OS(P=0.513).Multivariate analysis indicated that the NLN count was an independent prognostic factor for OS of jejunoileal NETs.A higher NLN count was associated with better OS(hazards ratio:0.641;95%confidence interval:0.519-0.793;P<0.001).Compared with 2 other prognostic systems,the NLN counts in this study had similar prognostic value in patients with jejunoileal NETs.Our findings suggest that the NLN count is an important independent prognostic factor for patients with jejunoileal NETs,and that it is a good adjunct for disease staging.